Dr. Lawrence J. Appel is a promising young faculty member who has made a substantial commitment to a career in clinical investigation. This commitment is evidenced by pursuit of advanced clinical and research training including a Chief Residency in Internal Medicine, a Masters Degree in Public Health, and a three year clinical research fellowship. More importantly, his training provides a solid foundation for him to address clinical research problems in a methodologically rigorous fashion. To this end, the proposed study builds upon his previous research efforts and addresses a question of fundamental importance to the hypertension research, health care provider, and health policy communities. Cardiovascular risk prediction remains imprecise due in part to suboptimal measurement of risk factors such as blood pressure (BP). Ambulatory BP monitoring (ABPM) represents a potentially important advance in the measurement of BP, but its role in cardiovascular risk prediction remains unproven. To answer this question, the CIA applicant will initiate a concurrent, prospective study designed to assess the impact of ABPM on cardiovascular risk prediction in a population at enormous risk for cardiovascular disease, renal transplant recipients. The environment and resources available to the CIA candidate are impressive. Dr. Paul K. Whelton, an accomplished investigator with expertise in the fields of hypertension, renal disease epidemiology and cardiovascular epidemiology, is the candidate's research mentor and will serve as his sponsor. In this role, Dr. Whelton will ensure that the candidate benefits from the tremendous resources of the Johns Hopkins Medical Institutions, particularly those of the Outpatient General Clinical Research Center and the Welch Center for Prevention, Epidemiology and Clinical Research. Receipt of a CIA will complement these resources by providing the candidate with the protected time necessary for him to reach his full potential as a clinical investigator.